From: Nicholas Piggin <npiggin@gmail.com> Date: Tue, 10 Apr 2018 11:49:33 +0000 (+1000) Subject: powerpc/powernv: Fix OPAL NVRAM driver OPAL_BUSY loops X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=25b6ee378dc43fff21e778f1a21cb7e6dffa6e1a;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git powerpc/powernv: Fix OPAL NVRAM driver OPAL_BUSY loops commit 3b8070335f751aac9f1526ae2e012e6f5b8b0f21 upstream. The OPAL NVRAM driver does not sleep in case it gets OPAL_BUSY or OPAL_BUSY_EVENT from firmware, which causes large scheduling latencies, and various lockup errors to trigger (again, BMC reboot can cause it). Fix this by converting it to the standard form OPAL_BUSY loop that sleeps. Fixes: 628daa8d5abf ("powerpc/powernv: Add RTC and NVRAM support plus RTAS fallbacks") Depends-on: 34dd25de9fe3 ("powerpc/powernv: define a standard delay for OPAL_BUSY type retry loops") Cc: stable@vger.kernel.org # v3.2+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- diff --git a/arch/powerpc/platforms/powernv/opal-nvram.c b/arch/powerpc/platforms/powernv/opal-nvram.c index ba2ff06a2c98..1bceb95f422d 100644 --- a/arch/powerpc/platforms/powernv/opal-nvram.c +++ b/arch/powerpc/platforms/powernv/opal-nvram.c @@ -11,6 +11,7 @@ #define DEBUG +#include <linux/delay.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/of.h> @@ -56,8 +57,12 @@ static ssize_t opal_nvram_write(char *buf, size_t count, loff_t *index) while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { rc = opal_write_nvram(__pa(buf), count, off); - if (rc == OPAL_BUSY_EVENT) + if (rc == OPAL_BUSY_EVENT) { + msleep(OPAL_BUSY_DELAY_MS); opal_poll_events(NULL); + } else if (rc == OPAL_BUSY) { + msleep(OPAL_BUSY_DELAY_MS); + } } if (rc)